Caulking gun



FIG. 1 is a perspective view from above and to the left of the caulking gun which is the subject of my new design;

FIG. 2 is a perspective view from above and to the right of the caulking gun;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a right side elevational view thereof, the left side elevational view being a mirror image thereof;

FIG. 6 is a bottom plan view thereof; and,

FIG. 7 is a top plan view thereof.

The broken lines in the drawings depict environmental subject matter only and form no part of the claimed design. 

The ornamental design for a caulking gun, as shown and described. 